With the rapid develop of display technology, touch screens have been widely used in daily lives. Currently, according to the constituent structure, the touch screen can be classified into: an add on mode touch panel, an on cell touch panel, and an in cell touch panel. Among them, the add on mode touch panel is manufactured by separately forming a liquid crystal display (LCD) and a touch screen and then adjoining them together to form an LCD panel with touch function. The add on mode touch panel has shortcomings such as high manufacturing cost, low light transmittance, and thicker module. The in cell touch panel, however, is favored by major panel manufactures since its touch electrodes of the touch screen are embedded inside the LCD panel, thereby reducing the overall thickness of the module and greatly reducing the manufacturing cost of the touch screen.
At present, the existing in cell touch screen detects a position of the finger touch according to the mutual capacitance or self-capacitance principle. According to the self-capacitance principle, a plurality of self-capacitive touch electrodes may be arranged in the same layer and insulated from each other in the touch screen. When the human body does not touch the screen, the capacitance born by each touch electrode may be a constant value, when the human body touches the screen, the capacitance born by the corresponding touch electrode may be the constant value superimposed on the body capacitance, and the touch position may be judged by a touch detecting chip by detecting the change in the capacitance value of each touch electrode during the touch period. As the human body capacitance may act on all of the self-capacitance, it is possible to improve the touch signal to noise ratio and thus improve the accuracy of touch sensing in comparison to the mutual capacitance touch screen, in which the capacitance caused by human body touch may act only on the projective capacitance in the mutual capacitance and thus the change caused by the touch is larger than that in the mutual capacitance touch panel.
It should be noted that, information disclosed in the above background portion is provided only for better understanding of the background of the present disclosure, and thus it may contain information that does not form the prior art known by those ordinary skilled in the art.